The use of sheet metal studs is a growing trend in new housing and office construction, because sheet metal studs are generally less expensive than wooden studs. Sheet metal studs typically comprise a galvanized steel sheet which is formed to be generally U-shaped in cross-section. In most cases, sheet metal studs are formed from light gauge steel, typically, 25 or 26 gauge galvanized steel.
Traditional nails are not usable to secure plywood sheet or drywall panels to sheet metal studs, as they provide no fastening power. Typically, some type of screw threaded fastener is needed to secure such materials to the sheet metal stud.
Conventional drywall fasteners may be used to mount drywall to sheet metal studs, since the gypsum material which is used in drywall sheets does not bind with the drywall fasteners and the drywall fasteners can pierce and be secured to the sheet metal.
However, conventional plywood sheet materials cannot easily be mounted to sheet metal studs with such drywall fasteners. Typically, when installed with a power tool such as a power screwdriver, the drywall fasteners will cause separation of the plywood sheet from the sheet metal stud and may strip out the hole in the sheet metal so that the plywood sheet is not securely fastened to the sheet metal stud. In addition, the heads of conventional drywall fasteners will not countersink in plywood, such that even if carefully installed so as to avoid jacking of the plywood sheet or stripping of the hole in the sheet metal, the drywall fastener must still be manually screwed in to achieve a countersunk head. If the head is not properly countersunk, it can create problems for subsequent finish carpentry and/or decorative painting, as a flat surface is typically needed to insure a professional finished look to the wall.
Another fastener used for connecting sheet materials to metal members is the screw sold under the registered trademark "TEKS" by Illinois Tool Works, Inc. This screw is illustrated for example in U.S. Pat. Nos. 3,524,378 and 4,275,541 (at FIGS. 6 and 7) and uses a cutting drill end joined with threaded and unthreaded shank sections. The TEKS screw is used for connecting sheet materials to structural steel members but is not usable to attach sheet materials to light gauge sheet metal, as the drill end will cut a hole that is too large to provide any holding power for the fastener.